Agreed ... go to Piedmont Hawthorne; fees will be pretty reasonable. I have been there many times in everything from a Cherokee to a King Air and have been treated well. Their van will drive you to/from the NASM annex as well I'm sure. Request 1L/19R if you can as it will save you a ton of taxi time versus the other runways. Potomac is pretty good about asking inbound GAs their parking location and giving them the proper runway if traffic permits.